Dust in many Salinas Valley homes carries traces of pesticides, a recent study reported.

In the largest study of its kind, researchers searched hundreds of local homes for tiny pesticide compounds sticking to dust layers and discovered widespread residues of 22 private and agricultural-use products.

The study was conducted by an investigator from the state Department of Public Health and researchers with the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) with the University of California, Berkeley.

Although scientists have linked some pesticide exposure to illness and developmental disorders in children, Asa Bradman, an associate director of CHAMACOS, cautions against jumping to conclusions.

CHAMACOS began recruiting pregnant women in the Salinas Valley for a longterm study of prenatal and infant chemical and allergen exposure in 1999. The center sampled study homes in 1999 and 2000 with a modified vacuum cleaner.

“We’re all exposed to a mix of compounds,” Bradman said. “We’re trying to understand that mix.”

The most common pesticides they found were permethrins – a popular weapon against home insect invasions – and chlorpyrifos. The U.S. Environmental Protection Agency banned chlorpyrifos for home-use in 2001, but it’s still a big player in agriculture.